Systemic-Onset Juvenile Idiopathic Arthritis

Abstract

Systemic juvenile idiopathic arthritis (SJIA) is a disease of unknown etiology characterized by arthritis and systemic symptoms. Evidence shows that SJIA is probably not a single disease but a diverse group of clinically and genetically distinct illnesses. It is classified both as one of the Juvenile idiopathic arthritis (JIA) categories and also among the autoinflammatory diseases. SJIA is probably the most severe forms of JIA, causing considerable morbidity and mortality. The macrophage activation syndrome (MAS), a form of secondary hemophagocytic lymphohistiocytosis (HLH), often appears in SJIA individuals and it still carries significant mortality. The constant growth of knowledge about the pathogenesis and the development of target therapies with the different biological agents have transformed the course and prognosis of children with this entity.